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D. FOSTER AND E. P. KELLEY.

HEADLIGHT LENS.

APPLICATION FILED FEB. I0. I919.

Patented Nov. 25, 1919.

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DONOVAN FOSTER, OF SEATTLE, WASHINGTON, AND FREDERICK P, KELLEY, OF CHICAGO, ILLINOIS, ASSIGNORS OF ONE-FOURTH TO EDWARD W. TODD, OF

LOS ANGELES, CALIFORNIA.

HEADLIGHT-LENS.

Application filed February 10, 1919.

T all whom it may concern:

Be it known that we, DONOVAN Fos'rna, a citizen of the U. S., residing at Seattle, King county, State of lVashington, and

FREDERICK P. KELLEY, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Headlight-Lenses, of which the following is a specification.

This invention relates to lenses for headlights of motor vehicles; and its object is the improvement of lenses of this character for the purpose of regulating the light rays to most efticientl illuminate the track in advance of the v hicle with an absence of y j I on the lower portio of the front face, to

glare.

The invention con ists in the novel construction, adaptatio ri\and combination of devices, as-\ vill be hereinafter described and claimed. w

In the accompanying fi'drawings,--. Figure 1 is a front elevation; and- Fig. 2 is a-rear elevation of a lense embodying our improvements. Figs. 3 and 4 are h rizontal sections through 33 and l4. o the preceding views. Fig. 5 is a vertical longitudinal section of the lens applied to a headlight re fiector. Fig. 6 is a horizontal sectional View of the same, take-n substantially on line 6-6 of Fig. l, the lens section being shown partly above and partly below the headlight axis.

In carrying out our invention, a lens is 3 formed on its inner or rear face (see Figs. 2 and 5) with superposed horizontally arranged prisms 10 10 10 and 10 of approximately equal heights, and disposed to have the under surface 11 of the prism 10 0 slightly below the horizontal axis {IF-17 0f the headlight. The rear surfaces 12 and 12 of the two lower prisms are inclined to a greater angle from a vertical plane than the corresponding, faces 12 and 12 of the two upper prisms.

The lens is formed to provide in its outer or front face a series of vertically arranged concavities 13 extending upwardly from the plane of the prism surface 11 and having below the latter a series of vertically arranged protuherant convex elements 14. The surfaces 13 and 14 of the aforesaid concavitiesand convex elements are formed of cylindrical arcs.

Specification of Letters Patent.

Patented Nov. 25, 1919.

Serial No. 275,980.

As illustrated, the lens is provided with a rim portion 15 having inner plane surfaces 16 to fit against the rim 17 of a reflector 18 and an outer plane surface 19 against which is seated the ring (not shown) by which the lens is secured in place.

The operation of the lens and the functions of its; various features may be eX- plained as follows:

Referring to Fig. 5, the direct and reflected rays indicated by A from a source of light or filament F, are caused by the lens prisms to be bent downwardly, as at A upon the road bed in front of the car. The rays passing through tie lens, moreover, are efi'ected by the luse of the convexities cause the reflected eams R from the filamentig. 6) to be diffused laterally, while thed'irect beams D are caused by said conve xities to converge and be approximately parallel, as indicated by D The concavities in the upper portion of the front face serve to cause a lateral diffusion, as R of the reflected beams R and to-diverge, as D the direct rays D of the.

lamp filament so as to render them less trying or objectionable to a passing pedestrian or driver owing to the smaller cone of light gathered by the pupil of the eye. F urther more, by extending the light-diminishing concavities below the horizontal'axis of the headlight, there is no glare from the filaments direct rays apparent to an observer when viewed from above a plane projected through such axis.

What we claim, is+

1. A substantially circular clear plate headlight lens having a face formed to refract downwardly all rays passing through the lens, means upon the upper half of the other face of said lens to cause divergence of all reflected parallel rays passing through said upper half of the lens and to cause greater divergence of alldiverging direct rays passing therethrough, and means upon the lower half of said other face of the lens to cause intersection of all reflected parallel rays passing through said lower half of the lens and to substantially parallelize the rays of bundles of diverging direct rays passing therethroughf 2. A substantially circular clear plate headlight lens having a face formed to refract downwardly all rays passing through the lens, a plurality of vertical directly connected minuscylindrical lenses upon the upper half of the other face of said lens to cause divergence of substantially all rcflccted parallel rays passing through said upper half of the lens and to cause greater divergence of substantially all diverging direct rays passing therethrougln-and a plurality of vertical directly connected plus cylindrical lens upon the lower half of said other face of the lens to cause intersection of'substantially all reflected parallel rays passing through said lower half of the lens and to substantially parallelizer the rays of bundles of diverging direct rays passing therethrough.

3. A substantially circular clear plate headlight lens having a plurality of horizontal transverse prisms on one face formed to refract downwardly all rays passing through the lens, means upon the upper half of the other face of said lens to cause divergence of all reflected parallel rays passing through said upper half of the lens and to cause greater divergence of all diverging direct rays passing therethrough, and means upon the lower half of said other face of the lens to cause intersection of all reflected parallel rays passing through said lower half of the lens and to substantially parallelize the rays of bundles of diverging direct rays passing therethrough. V

4. A substantially circular clear plate headlight lens having a plurality of horizontal transverse prisms on one face formed to refract downwardly all rays passing through the lens, a plurality of vertical directly connected minus cylindrical lenses upon the upper half of the other face of said lensto cause divergence of all reflected parallel rays passing through said upper half of the lens and to cause greater divergence of all diverging direct rays passing therethrough, and a plu rality of vertical directly connected plus cylindrical lens upon the lower half of said other face of the lens to cause intersection of all reflected parallel rays passing through said lower half of the lens and to substantially parallelize the rays of bundles of diverging direct rays passing therethrough.-

Signed at Seattle, \Vashington, this 3rd .day of February. 1919.

DONOVAN FOSTER. FREDERICK P. KELLEY. Witnesses:

PIERRE BARNES, I E. PETERSON. h 

